Channel biased ballast holddown



Feb. 23, 1960 Filed Nov. 8. 1957 C. M. MOSER CHANNEL BIASED BALLAST HOLDDOWN 2 Shasta-Sheet 1 IIIIIIIIIIIIIIII FIG. 6

INVENTOR. CARL M. MOSER BY E L PM* ATTORNEYS Feb. 23, 1960 c. M. MOSER 2,925,982

CHANNEL BIASED BALLAST HOLDDOWN Filed NOV. 8, 1957 2 Sheets-Sheet 2 INVENTOR.

ATTOPA/CVJ United States Patent 2,925,982 CHANNEL BIASED BALLAST HOLDDOWN Carl M. Moser, Cleveland, Ohio, assignor to John C. Xirden Company, Cleveland, Ohio, a corporation of bio Application November 8, 1957, Serial No. 696,587 4 Claims. (Cl. 248-361) This invention relates to a fastening device and is particularly adapted to firmly secure objects within flanged channel members.

This application is a continuation-in-part of my copending application, Serial No. 520,838, filed July 8, 1955, now abandoned, and assigned to the present assignee.

An object of the invention is to provide a fastener of the type described which is a quick-connect fastener employing no threaded connections, which is strong and firm in anchoring even heavy objects such as ballast boxes and which requires no drilling or other modification whatsoever of the channeling in which the object to be fastened or anchored is to be positioned.

One embodiment of this invention contemplates the provision of a spring strap which is provided with a fulcrum-detent member which at one time serves to induce clamping engagement downwardly on the mounted member and accommodates ready fastening of the device. Because no modification whatsoever of the channeling with which this embodiment of invention is used is required, manufacturing costs of channel-housed assemblies which may employ the invention, such as fluorescent light fixtures, may be very substantially reduced. According to another embodiment of this invention applicable to secure objects of another construction, a spring strap securable within the channel member is provided with appropriate recesses in one side for receiving and engaging detents extending from the bottom of the channel member. Such detents may simply be projections quickly and easily punched inwardly from the bottom of the channel member.

These and other objects and advantages of the invention'will be more clearly understood by referring to the following description of an example of the invention, together with the accompanying drawings in which:

Figure 1 illustrates a flanged channel in connection with which the invention may be employed.

Figure 2 illustrates a typical ballast box to be secured within the channel shown in Figure 1.

Figure 3 illustrates a spring strap contemplated by the invention.

Figures 4, 5 and 6 are cross-sectional views illustrating several stages in the assembly and fastening of the parts, the body of the ballast box being omitted from Figures 5 and 6 for clarity.

Figure 7 illustrates certain alternative details of the invention.

Figure 8 illustrates another form of ballast utilizable in channels shown in Figure 1.

Figure 9 illustrates a modified form of resilient strap for securing the ballast of Figure 8 within the channel.

Figure 10 illustrates in perspective the relative disposition of channel, ballast and resilient strap in securing position thereof.

Figure 11 is a cross-sectional view taken along section 1sl...1.1 o Fig 10..

Many objects such as the ballast box 10 illustrated in Figure 2 are provided with base flanges 11 in which holes 12 are drilled which are intended to receive mounting screws or other conventional fasteners. It is frequently desired to securely mount such objects within housing channels which form the body of final assemblies such as fluorescent light fixtures. One highly suitable form of channel is shown in Figure 1, the channel 13 having a simple cross-section and being provided with inwardly extending flanges at its open long side adapted to be engaged by cover means (not shown).

The invention relates to the problem of fastening the flanges 11 down against the bottom of the channel 13 by simple means which do not involve any drilling or other modification of the channel but which will result in firm anchoring of even a very heavy anchor box.

A clip or strap 15 is provided which may have the general conformation of the inside of the channel 13. The clip comprises a springy metal strap. A struck-out downwardly depending fulcrum-tab 16 is provided on the bottom side of the strap 15. An additional and similar but somewhat shorter tab 17 may also be provided. It will be apparent to those familiar with metal fabricating that the manufacture of this strap can be extremely simple.

The parts are assembled as follows. The object being mounted, such as the ballast box, is placed in the channel at the desired longitudinal location, as shown in Figure 4. A strap is then placed in preliminary position as shown in Figure 5, with one end 18 of the strap being received under its associated flange 14. The length of the tab 16 prevents the other end 19 of the strap from being received under its associated flange 14 in a manner which will be apparent from the drawing. At this stage the tab 16 may be partially engaged in one of the holes 12, and the additional tab 17, if such an additional tab is provided, may be in partial engagement with the other of the holes 12.

The root of the strap adjacent the end "19 is then pressed downwardly, the tab 16 acting as a fulcrum. Since the end 18 is caught under a flange 14, the corner of the strap between the end 18 and the tab 16 tends to toggle inwardly (downwardly). With sufficient pressure, the end 19 of the strap is carried below its associated flange 14 and springs into engaged position, leaving the parts in the final position shown in Figure 6. Both ends of the bottom of the strap 15 are held in tight engagemerit with the top of the flange 11, and the tabs 16 and 17 are driven and held home in the holes 12. The deformation of the strap 15 is slightly exaggerated in Figure 6 to more clearly illustrate the fastening action of the parts. The tabs 16 and 17 are preferably proportioned to occupy the full width of the holes 12, although they are shown as of slightly reduced width in the drawings for PHIPOSGS'Of clarity.

A strap similar to the strap 15 is employed to anchor the opposite end of the ballast box 10. Thus, without any drilling or other modification of the channel, the ballast box is very quickly and securely mounted. 'It may be dismounted by prying one end 18 or 19 of each fastening strap out from under its flange 1'4, as with a screwdriver.

Current Underwriters Laboratories requirements for fluorescent fixtures call for positive electrical connections between ballast box and fixture body. The mounting or fastening as above disclosed is so simple that there are no connections to the fixture body or channel 13. Accordingly, in this particular application it may be desirable to ground oneside of one strap to a side of the channel 13 with a single screw 20, as shown in Figure 7. The additional mechanical strength attained by such single screw also assures thatthe heavy ballast box will not shift longitudinally even a slight amount within the channel 13, even when the channel is dropped on its end, as may happen during shipment of the light fixtures of which the several described elements form a major structural part. Alternatively, one or more shallow lances or shoulders, such as that shown at 21 in Figure 7, may be provided in the sides of the channel 13 where extremely heavy end loads are to be encountered but where ground connections are not of importance. Such lances or shoulders are positioned to engage one or both edges of one or both straps. Provision of such modifications of the channel, simple as they are, is necessary or desirable only when extremely heavy endwise shock loads are to be encountered.

According to another embodiment of the invention shown in Figures 9, and 11 of the drawings, provision is made for securing a ballast 110 as shown in Figure 8 of the drawings and having a flange 112 of generally semi-oval contour extending therefrom at one end and a similar flange 114 extending therefrom at the other end. The ballast 110 may be entirely the same or similar to the ballast 10 described hereinabove with the exception of the contour of the flanges 112 and 114.

For securing one end of the ballast 110 in a channel 116 as shown in Figures 10 and 11 of the drawings, a pair of tangs or detents 118 and 120 may be punched inwardly out of the intermediate or bottom surface 117 of the channel 116 for engagement with a metal strap shown generally at 122 and provided for cooperation with the described tangs and the channel, itself. Strap 122 comprises a resilient, generally U-shaped member having a pair of substantially straight side sections 123 and 124 joining an intermediate section 125 with a pair of recesses 126 and 127 preferably of semi-circular contour at spaced points along one side thereof. Intermediate section 125 is preferably curved so as to be concaved upwardly as shown in Figure 9 and side sections 123 and 124 form an obtuse angle with intermediate section 125 in the free condition thereof as shown in Figure 9. The spacing between recesses 126 and 127 is substantially equal to that between tangs 118 and 120 so as to enable engagement of the same at intermediate points of the recesses as shown in Figures 10 and 11.

In assembling the ballast 110 in the channel section, the ballast is disposed with flange 112 in abutment with both tangs 118 and 120 and resting upon the intermediate surface 117 of the channel and thereafter one side section 123 of the metal strap 122 is disposed beneath lip 130 of channel 116 as shown in Figure 11. The lower end of the section 123 is forced into engagement with the adjoining side wall and bottom of the channel and thereafter the intermediate section 125 of the strap 122 is disposed across the top of the flange 112 with the recesses 126 and 127 engaging respective tangs 118 and 120. As the last step in this assembly, the remaining side section of strap 124 is forced into engagement with the remaining side wall of channel 116 beneath the lip 132 of the channel. In this position intermediate section 125 is distorted from its free position contour into a substantially straight member and the side sections 123 and 124 are distorted to form substantially a right angle with intermediate section 125 whereby the resiliency of the strap is effective to cause the ends of sections 123 and 124 to engage and push against lips 131i and 132 and also to tightly engage and push against the side walls of channel 116.

It is to be understood that a similar strap cooperable with a pair of detents and flange 114 is adaptable to secure the remaining end of the ballast 110 whereby the same may be firmly secured at each end against axial or lateral movement relative to the channel member.

According to this embodiment of the invention, the ballast 110 is retained in the channel 116 securely to withstand endwise shocks applied to the ballast without injury or deformation to any part thereof. The engagement of strap 122 with the tangs 118 and 120 is at a low portion of the tangs whereby the bending arm through which flange 112 acts is small and accordingly, the-bending moment applied to the tangs is also relatively small.

Having thus described this invention in such full, clear, concise and exact terms. as to enable any person skilled in the art to which it pertains to make and use the same, and having set forth the best mode contemplated of carrying out this invention, I state that the subject matter which I regard as being my invention is particularly pointed out and distinctly claimed in what is claimed, it being understood that equivalents or modifications of, or substitutions for, parts of the above specifically described embodiment of the invention may be made without departing from the scope of the invention as set forth in what is claimed.

What is claimed is:

1. An assembly comprising a support member have a bottom portion and upstanding side portions, abutment means on each side portion facing said bottom portion, a part mounted on said support member having a mounting portion extending along the bottom portion of said member, and a resilient mounting strap having a base extending transversely of the bottom portion of said support member and having upstanding side portions, abutment means on each side portion of said strap facing away from the base thereof and toward the abutment means on the side portions of said support member, the base of said strap having a pressure-exerting portion engaging the mounting portion of said part, the abutment means of the side portions of said strap and said support member being in resilient pressure engagement with one another when said member, part, and strap are assembled, the normal distance between the underside of the pressure-exerting portion of said strap and its abutment means exceeding the corresponding distances between the upper portion of the mounting portion of said part as it rests upon the bottom portion of said support member and the abutment means of said support member when said strap is free of said support member; and when said strap is resiliently mounted in said support member the pressure exerting portion of the base of said strap finnly pressing the mounting portion of said part against the bottom portion of said support member, the remainder of the base of said strap exerting substantially no force against the base portion of said support member to insure firm retaining pressure against the mounting portion of said part to press it against the bottom portion of said support member.

2. An assembly comprising a support member have a bottom portion and upstanding side portions terminating in inwardly facing flanges, a part mounted on said support member having a mounting portion extending along the bottom portion of said member, and a resilient mounting strap having a base extending transversely of the bottom portion of said support member and having upstanding side portions, the base of said strap having a pressure-exerting portion engaging the mounting portion of said part, the ends of the side portions of said strap and the flanges of said support member being in resilient pressure engagement with one another when said member, part, and strap are assembled, the normal distance between the underside of the pressure-exerting portion of said strap and the ends of its side portions exceeding the corresponding distances between the upper portion of the mounting portion of said part as it rests upon the bottom portion of said support member and the underside of the flanges of said support member when said strap is free of said support member; and when said strap is resiliently mounted in said support member the pressure exerting portion of the base of said strap firmly pressing the mounting portion of said part against the bottom portion of said support member, the remainder of the base of said strap exerting substantially no force against the base of said support member to insure firm retaining pressure against the mounting portion of said part to press it against the bottom portion of said support member.

3. An assembly comprising a support member have a bottom portion and upstanding side portions, abutment means on each side portion facing said bottom portion, a part mounted on said support member having a mounting portion extending along the bottom portion of said member, and a resilient mounting strap having a base extending transversely of the bottom portion of said support member and having upstanding side portions, abutment means on each side portion of said strap facing away from the base thereof and toward the abutment means on the side portions of said support member, detents extending upwardly from the bottom portion of said support member, notches in the base of said strap for fitting said detents, the base of said strap having a pressure-exerting portion engaging the mounting portion of said part, the abutment means of the side portions of said strap and said support member being in resilient pressure engagement with one another when said member, part, and strap are assembled, the normal distance between the underside of the pressure-exerting portion of said strap and its abutment means exceeding the corresponding distances between the upper portion of the mounting portion of said part as it rests upon the bottom portion of said support member and the abutment means of said support member when said strap is free of said support member; and when said strap is resiliently mounted in said support member the pressure exerting portion of the base of said strap firmly pressing the mounting portion of said part against the bottom portion of said support member, the remainder of the base of said strap exerting substantially no force against the base portion of said support member to insure firm retaining pressure against the mounting portion of said part to press it against the bottom portion of said support member.

4. An assembly comprising a support member have a bottom portion and upstanding side portions, abutment means on each side portion facing said bottom portion, a part mounted on said support member having a mounting portion extending along the bottom portion of said member, and a resilient mounting strap having a base extending transversely of the bottom portion of said support member and having upstanding side portions, abutment means on each side portion of said strap facing away from the base thereof and toward the abutment means on the side portions of said support member, interfitting detents in the base of said strap and in the mounting portion of said part, the base of said strap having a pressure-exerting portion engaging the mounting portion of said part, the abutment means of the side portions of said strap and said support member being in resilient pressure engagement with one another when said member, part, and strap are assembled, the normal distance between the underside of the pressure-exerting portion of said strap and its abutment means exceeding the corresponding distances between the upper portion of the mounting portion of said part as it rests upon the bottom portion of said support member and the abutment means of said support member when said strap is free of said support member; and when said strap is resiliently mounted in said support member the pressure exerting portion of the base of said strap firmly pressing the mounting portion of said part against the bottom portion of said support member, the remainder of the base of said strap exerting substantially no force against the base portion of said support member to insure firm retaining pressure against the mounting portion of said part to press it against the bottom of said support member.

References Cited in the file of this patent UNITED STATES PATENTS 2,158,728 Peters May 16, 1939 2,168,721 Tinnerman Aug. 8, 1939 2,257,855 Place Oct. 7, 1941 2,325,691 Litwin Aug. 3, 1943 2,394,728 Tinnerman Feb. 12, 1946 2,460,722 Waara Feb. 1, 1949 2,625,360 Hall Jan. 13, 1953 

